DE4440409C2 - Process for the preparation of high molecular weight polyamideimide resins - Google Patents

Description

The present invention relates to an economical interesting process for the production of polyamideimide Resins. In particular, it concerns a procedure for Production of polyamideimide resins by dissolving one Anhydrous aromatic tricarboxylic acid (or its Derivatives) and an aromatic diamine in a polar Solvent and the direct polymerization of the solution in Presence of a polymerization catalyst.

The present invention also relates to a method for Manufacture of high polyamideimide resins Molecular weights and in high yield in a simple Way at relatively low temperatures in one short time.

The molecular structure of the polyamideimide resins differs depending on the monomers used. Typical examples of these are represented by the following formula (I):

where R

and by polycondensation of trimellitic acid (or their derivatives) as an aromatic tricarboxylic acid component m-phenylenediamine and diaminodiphenyl ether as aromatic Diamine component can be produced.

Polyamideimide resins of the formula (I) are disclosed in U.S. Patent No. 4,045,407 and Japanese Patent Publication No. Hei 07-0422. They are transparent and non-crystalline resins that have the following properties:

• 1. Your heat distortion temperature (heat distortion temperature) is 278 ° C and its permanent The heat resistance temperature is above 200 ° C. she have excellent heat resistance and can in the wide temperature range from -200 ° C to 260 ° C used become.
• 2. They not only have high mechanical strength but they also show good physical properties at room temperature Reinforcement properties for conventional ones Plastic materials, even at temperatures above from 200 ° C. They also show excellent impact resistance.
• 3. They show creep resistance.
• 4. They have a low linear expansion coefficient of 4 × 10 ^-5 cm / cm. ° C, which can be reduced to less than half by using a filler.
• 5. They have excellent insulation properties, a high volume resistance and show one Flame resistance of UL 94 V-O without the addition of additives.
• 6. Because of their composition they have like PTFE and Graphite has good abrasion resistance. They are suitable as Sliding parts under heavy load as they are good  Self-lubrication, abrasion resistance and strength as well Have elasticity even at high temperatures.
• 7. They show good chemical resistance and are stable in hydrocarbon solvents, in Concentrated aqueous alkali solutions, however, apply to watch out.
• 8. They show good ultraviolet and Radiation resistance.

Examples of methods for the production of polyamideimide Resins generally include the isocyanate and the Acid chloride methods.

The isocyanate method involves the condensation of aromatic diisocyanates with aromatic Tricarboxylic anhydrides to polyamideimides without losing the Stage of polyamic acid to go through that as an intermediate polymer in Japanese Laid-Open No. SHO 48-19274 and the U.S. Patent No. 3 541 038 (1970).

The acid chloride method involves the condensation of aromatic tricarboxylic acid chlorides with aromatic Diamines. This method is divided into the "Polymerization at low temperature in a homogeneous solution" and in the "precipitation polymerization at lower Temperature ". Typically, the polymerization involves low temperature in a homogeneous solution Polymerization reaction at room temperature in one does not aqueous polar solvents such as. B. N, N-Dimethylacetamide (hereinafter abbreviated as DMAC) by Standard Oil Co., was developed in the US and in the US patent No. 3,920,612 (1975). Typically, this includes Precipitation polymerization at low temperature Polymerization reaction in an organic solvent,  which is only slightly soluble in water, e.g. B. Methyl ethyl ketone (e.g. manufactured by Teijin Kasei Corp. in Japan) and an aqueous solvent using Triethylamine as a base, as in Japanese Laid-open publication No. SHO 46-15513. This Reaction is a kind of interfacial polymerization.

Another method for the production of polyamideimide resins is direct polymerization, which is direct Polymerization of aromatic diamines with aromatic Tricarboxylic acids in the presence of a dehydrogenation catalyst and in U.S. Patent No. 3,860,559 (1975) and Japanese Patent No. SHO 58-180532 is.

The problem with the isocyanate method, however, is that gelation occurs during the reaction and it because of the Formation of by-products is difficult, linear polymers to produce with high molecular weights. Therefore they have polyamideimide resins produced by this method reduced melt flow, poor processability in the Melt, mechanical properties and heat resistance and are therefore not suitable for use as Casting materials.

When polymerizing at low temperature and in Homogeneous solution can polymers with high molecular weights can be obtained if the very expensive Acid chlorides can be used. However, this means that Cost of raw materials very high. This one In addition, the method is carried out in two stages, which in the production of polyamic acid as Prepolymer and its imidation using a Dehydrogenation catalyst exist, it is necessary to Halogen compounds formed during the reaction  remove, making this method less economical becomes interesting. The problem also occurs with this method on that a modification of the molecular structure of the resins is almost impossible.

The precipitation polymerization at low temperature is in two stages in the precipitation of polyamic acid (polyamic acid) using very expensive acid chloride, Methyl ethyl ketone and water as a solvent and the subsequent treatment for ring closure exist as homogeneous polymerization carried out at low temperature. The polyamideimide resins that are manufactured in these two stages have a large molecular weight distribution and low molecular weights. Therefore, this method has none practical use.

Both the isocyanate and acid chloride methods are disadvantageous because the handling of the acid chlorides and the Isocyanate is difficult because both acid chlorides as well the isocyanates are sensitive to water, which is why this is Reaction process must be intercepted.

The direct polymerization method for polyamideimide resins involves the direct polymerization of aromatic diamines with aromatic tricarboxylic acid anhydrides (or their Derivatives) in the presence of polymerization catalysts. The Advantages of this polymerization method are that Procedure according to this method among the many Manufacturing process the simplest is the cost of that Starting materials and implementation are not high and that the Handling the monomers is easy. For these reasons a lot of research has been done in this area. examples for Polymerization catalysts used in this method Catalysts of the phosphoric acid type are used such as phosphoric acid and polyphosphoric acid (Japanese  Patent Publication No. SHO 62-21521 and SHO 62-291329), of the boric acid type such as boric acid and boric anhydride (French Patent No. 1,515,066 and Japanese Patent Publication No. 58 180 532) or triphenyl phosphite and phosphoric acid triesters (U.S. Patent No. 3,860,559). Around however when using expensive Polymerization catalysts and reactive monomers in the same molar ratio polymers with high To get molecular weight, it is necessary to complete the reaction at high temperatures of 200 ° C or above for longer Time to run. Therefore, even in the case of use of solvents with a high boiling point such as N- Methylpyrrolidone (hereinafter abbreviated as NMP), sulfolane or nitrobenzene formed by degradation of the monomers tar-like substances and resins formed in the reaction vessel as well as the one used in large quantities Polymerization catalyst built into the polymer, whereby unsatisfactory staining occurs and the physical Properties of the polyamide imide are deteriorated. Of another disadvantage of this method is that it due to side reactions and the associated Lowering the solubility of the polymer is difficult to linear To produce high molecular weight polymers. Especially this method is not economical because it is very expensive Polymerization catalyst can be used in large quantities must and the recovery of the catalyst is not possible is.

Given the problems with the above procedures the inventors have carried out extensive studies, to the difficulties with the known direct Polymerization method to overcome and a method for Manufacture of high polyamideimide resins Molecular weights, good heat resistance and good Find melt flow. As a result, the inventors now have  found that by dissolving an aromatic Tricarboxylic anhydride (or its derivatives) and one aromatic diamine in a polar solvent and subsequent polymerization of the solution obtained in Presence of polymerization catalysts polyamideimide resins can be produced with high molecular weights. The The present invention is based on these findings.

The present invention is based on the object Process for the production of high polyamideimide resins Molecular weights, good heat resistance and good To provide melt flow.

One aspect of the present invention is a method to provide for the production of polyamideimide resins, the dissolving an aromatic tricarboxylic acid and one aromatic diamine in a polar solvent, the Prepolymerize the solution obtained using of an acyl halogenating agent as the first Polymerization catalyst with a polyamideimide resin low molecular weight, and treating the latter with a phosphorus compound as the second Polymerization catalyst to use a polyamideimide resin to obtain high molecular weights.

Other tasks and benefits are for the Average person skilled in the art from the following description evident.

The present invention relates to a method for Manufacture of high polyamideimide resins Molecular weights.

The process for the production of polyamideimide resins (in hereinafter abbreviated as PAI resins) with an intrinsic  Viscosity of 0.4 dl / g or more is as follows: an acyl Halogenating agents such as inexpensive thionyl chloride as first polymerization catalyst is in a polar Solvent such as NMP is dissolved and then the Solution cooled to 5 ° C or less to form a complex receive. Add to the complex at room temperature aromatic tricarboxylic anhydride and stir for 1 h Room temperature. After adding the aromatic diamine subject the mixture to a 5 hour period Polymerization reaction at 50 to 130 ° C until the PAI resin with an intrinsic viscosity of 0.4 dl / g or less in a DMAC solution at a concentration of 0.5 g / dl 30 ° C is determined is obtained. The PAI resin will continuously a polymerization reaction in the presence a phosphorus compound as a second catalyst, e.g. B. Triphenyl phosphite (hereinafter abbreviated as TPP), subjected in an amount of 1-70 mol%, based on the molar sum of the aromatic used Tricarboxylic anhydrides and aromatic diamines to obtain high molecular weight PAI resins.

The present invention is detailed below explained.

As aromatic tricarboxylic acid anhydrides, which in the Processes according to the invention can be used trimellitic anhydride, tricarboxylic anhydride, 1,2,3- Benzenetricarboxylic anhydride, 1,2,4-, 1,4,5- and 2,3,6- Naphthalene tricarboxylic anhydride, 3,4,4 '- Benzophenoltricarbonsäureanhydrid and 3,4,4 '- Phenyl ether tricarboxylic acid anhydride. Examples of aromatic Tricarboxylic acid derivatives are esters of Trimellitic anhydride with alcohols, e.g. B. Trimellitic acid monoester compounds such. B.  Trimellitic acid monomethyl ester and Trimellitic acid monoethyl ester.

Examples of aromatic diamines used in the methods according to the invention can be used are Phenylene diamine, p-phenylene diamine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 4- Methyl 1,3-diaminobenzene, 4,4'-diaminodiphenylmethane, 3,4'- Diaminodiphenyl ether, 3,3'-dichloro-4, 4'- diaminodiphenylmethane, 3,3'-dimethoxy-4, 4 '- diaminodiphenylmethane, m-bis (paminophenoxy) benzene, p-bis (p aminophenoxy) benzene or m-xylene diamine.

These compounds can be used as such or in mixtures of two or more can be used if necessary. Under these are trimellitic anhydride and Trimellitic acid monomethyl ester, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, m-phenylenediamine and p- Phenylenediamine beneficial in terms of physical Properties such as heat resistance, melt flow and cost of the resin to be produced.

According to the invention, the first polymerization catalyst an organic or inorganic acyl halogenating agent e.g. B. thionyl chloride, p-toluenesulfonyl chloride, Sulfuryl chloride, cyanuric chloride and phosphorus trichloride used, with thionyl chloride in terms of cost and Properties is particularly advantageous.

According to the invention, as polar solvents, the one Can form complex with the first catalyst, and thus facilitate imidation, NMP, N-ethylpyrrolidone, N- Phenylpyrrolidone, N-phenylpiperidone, N-methylcaprolactam, N, N'-ethylenedipyrrolidone, N-phenyldipyrrolidone, Hexamethylphosphoric acid diamide (hereinafter referred to as HMPA  abbreviated), N-methyl-α-pyridone, N, N '-dimethylacetamide, Dimethylformamide and dimethylpropionamide are used. At the most preferred are NMP, N-methyl-α-pyridone and HMPA.

According to the invention, phosphorus compounds are used as the second catalyst. Examples of phosphorus compounds are trivalent phosphorus compounds of the formula (RO) ₃ P such as TPP, tricresyl phosphite, tricyclohexyl phosphite, dimethyl-m chlorophenyl phosphite and oxyethyl dipyridyl phosphite. R stands for aliphatic and aromatic substituents and examples of R are methyl, ethyl, butyl, i-butyl, 2-ethylhexyl, i-octyl, tolyl, nonyl, phenyl and diphenylnonyl. Apart from this, 5-bonded phosphorus compounds such as phosphoric acid, pyrophosphoric acid, m-phosphoric acid, phosphorus pentoxide and phosphorus pentachloride can also be used.

The PAI resins according to the invention can be obtained by using the aromatic tricarboxylic acid anhydrides and aromatic diamines are produced in an equimolar amount. The concentration of the reactants is preferably 7 to 30% by weight. If the concentration is less than 5% by weight is, the reaction is no longer economical, and if the concentration is above 30 wt .-% occurs Gelation one. The amount of the first Polymerization catalyst is 5 to 80 mol% and preferably 40 to 60 mol%, based on the molar sum of used aromatic tricarboxylic acid anhydrides and aromatic diamines. The reaction temperature is selected from the range of 50 to 130 ° C, and the reaction time is in the range of 1 to 5 hours. The amount of the second Polymerization catalyst is 1 to 70 mol% and in particular 5 to 50 mol%, based on the molar sum of used aromatic tricarboxylic acid anhydrides and aromatic diamines. The reaction temperature is 70 to 130 ° C and the reaction time is 1 to 5 h.  

The PAT resins produced according to the invention have one intrinsic viscosity of 0.4 dl / g determined in a DMAC Solution at a concentration of 0.5 g / dl at 30 ° C. This PAI resins have been thoroughly imidated and can be used for casting, films and Coatings are used.

According to the invention, the method is relative low temperature of 130 ° C or less in a very short time Time, d. H. done in less than 5 h with PAI resins with high molecular weights, good heat resistance and good melt flow can be obtained. Furthermore there is no sign of deterioration due to solubility of side reactions as well as discoloration or Deterioration of physical properties due to the inclusion of tar substances. Therefore, the resins as a thermoplastic molding material and in particular as heat-resistant structural material in advanced Areas, e.g. B. the electrical and electronics or Aviation industry can be used.

The present invention will now be described with reference to following examples explained in more detail, the present invention is not limited to this and various changes within the inventive concept can be made.

example 1

237.8 g (2 mol) of thionyl chloride are added slowly Passing nitrogen into 2 l of NMP in a 25 l reactor, the one with a stirrer, a nitrogen inlet, a Temperature controller and a cooler is provided, solved and the solution is cooled to 5 ° C or less. After 30 min the solution is warmed to room temperature and heated for 30 min  kept at this temperature. One slowly adds to this solution 384 g (2 moles) of trimellitic anhydride and 2 l of NMP. After A stirred solution of 400 g becomes 0.5 to 1 h stirring (2 moles) diaminodiphenyl ether and 204 g (2 moles) triethylamine in 3 l NMP slowly added within 1 to 2 h and the Solution at 70 ° C subjected to a three-hour reaction. To 310 g (1 mol, 25 mol%) of TPP are added to the reaction mixture and during the three hour response the internal Temperature increased to 100 ° C. The reaction mixture is in a mixer (Waring Blender) with an excess of methanol treated to precipitate the polymer. The precipitated polymer is separated by filtration, several times with water and Washed methanol and then in vacuo at 120 ° C for 24 h dried, the polymer being obtained as a yellow powder. The intrinsic viscosity, measured in a dimethylacetamide Solution at a concentration of 0.5 g / dl at 30 ° C 0.93 dl / g.

The PAI produced was dissolved in dimethylacetamide, where the solids content was 10 to 15% by weight. The received Solution was placed on a glass plate and one one-hour curing treatment at 150 ° C, 250 ° C and 300 ° C subjected to obtaining PAI films.

Example 2

The procedure of Example 1 was repeated using the Difference that 155 g (0.5 mole, 12.5 mole%) TPP second Polymerization catalyst were added and then the Reaction was carried out continuously at 100 ° C. for 3 h, to get the PAI resin. The intrinsic viscosity, measured on a dimethylacetamide solution in a Concentration of 0.5 g / dl at 30 ° C was 0.85 dl / g.  

Example 3

The procedure of Example 1 was repeated using the Difference that 77.5 g (0.25 mol, 6.25 mol%) TPP as second polymerization catalyst were added and after the temperature was raised to 100 ° C, the reaction was carried out continuously at 100 ° C for 3 h in order to Obtain PAI resin. The intrinsic viscosity, measured on a dimethylacetamide solution at a concentration of 0.5 g / dl at 30 ° C was 0.65 dl / g.

Example 4

The procedure of Example 1 was repeated using the Difference that 38.8 g (0.125 mol, 3.125 mol%) TPP as second polymerization catalyst were added and after the temperature was raised to 100 ° C, the reaction was carried out continuously at 100 ° C for 3 h in order to Obtain PAI resin. The intrinsic viscosity, measured on a dimethylacetamide solution at a concentration of 0.5 g / dl at 30 ° C was 0.51 dl / g.

Example 5

The procedure of Example 1 was repeated using the Difference that 216 g (2 moles) of m-phenylenediamine instead of Diaminodiphenyl ether and 204 g (2 mol) triethylamine in 3 l NMP were dissolved to obtain the PAI resin. The intrinsic viscosity, measured on a dimethylacetamide Solution at a concentration of 0.5 g / dl at 30 ° C 0.86 dl / g.  

Example 6

The procedure of Example 1 was repeated using the Difference that 396 g (2 moles) of diaminodiphenylmethane instead of diaminodiphenyl ether and 408 g (4 mol) of triethylamine in 3 l of NMP were dissolved to obtain the PAI resin. The intrinsic viscosity, measured on a dimethylacetamide Solution at a concentration of 0.5 g / dl at 30 ° C 0.86 dl / g.

Example 7

The procedure of Example 1 was repeated using the Difference that 280 g (1.4 mol) diaminodiphenyl ether and 65 g (0.6 mol) of m-phenylenediamine were dissolved in 3 l of NMP and along with 158 g (2 moles) of pyridine were added to make the Obtain PAI resin. The intrinsic viscosity, measured on a dimethylacetamide solution at a concentration of 0.5 g / dl at 30 ° C was 1.25 dl / g.

Example 8

The procedure of Example 1 was repeated using the Difference that 240 g (1.2 mol) of diaminodiphenyl ether, 64.8 g (0.6 mol) m-phenylenediamine and 23.2 g (0.2 mol) Hexamethylenediamine were dissolved in 3 l NMP and together with 158 g (0.2 mol) of pyridine was added to add the PAI resin receive. The intrinsic viscosity, measured on a Dimethylacetamide solution with a concentration of 0.5 g / dl at a temperature of 30 ° C was 1.05 dl / g.

Comparative Example 1

237.8 g (2 moles) of thionyl chloride are in the same Reaction apparatus as in Example 1 dissolved in 2 l of NMP and  the solution cooled to 0 ° C. After 30 min the solution is on Warmed to room temperature and at this temperature for 30 min held. 384 g (2 mol) are added to this solution Trimellitic anhydride and 2 L NMP, and then the solution stirred at room temperature for 1 h. 400 g (2 moles) Diaminodiphenyl ether and 204 g (2 mol) of triethylamine are in 3 l NMP dissolved and slowly to the within 1 to 2 h previous solution added and the mixture is allowed to React at 70 ° C for 3 hours. After heating to 100 ° C and three-hour reaction without the addition of TPP is after the in Procedure described in Example 1 is the PAI resin receive. The intrinsic viscosity, measured on a Dimethylacetamide solution at a concentration of 0.5 g / dl at 30 ° C was 0.25 dl / g.

Comparative Example 2

384 g (2 mol) trimellitic anhydride and 4 l NMP are in the same reaction apparatus as given in Example 1 and the mixture is added first without the addition of thionyl chloride Polymerization catalyst for 1 hour at room temperature touched. 400 g (2 mol) diaminodiphenyl ether and 204 g (2 mol) Triethylamine are dissolved in 3 l of NMP and the solution is slowly added to the previous solution and stirring 3 h at 70 ° C. After heating to 100 ° C, add 310 g (1 mole) TPP and three hour reaction will Reaction mixture worked up according to Example 1. It found however, no polymerization reaction takes place.

Comparative Example 3

237.8 g (2 mol) of thionyl chloride are dissolved in 1 l of NMP in the same apparatus as in Example 1 and the solution is cooled to 0 to 5 ° C. After about 30 minutes, the solution is warmed to room temperature and held at that temperature for 30 minutes. 384 g (2 mol) of trimellitic anhydride and 400 cm ^{3 of} NMP are slowly added to the solution. After stirring for 0.5 to 1 hour at room temperature, 400 g (2 mol) of diaminodiphenyl ether and 20.4 g (2 mol) of triethylamine are added so that the concentration of the reactants is 35% by weight and the mixture is left at 70 ° for 4 hours C react. At this time, the intrinsic viscosity of a sample taken from the reaction mixture was 0.23 dl / g, measured on a dimethylacetamide solution with a concentration of 0.5 g / dl at 30 ° C. After adding 310 g (1 mol) of TPP and raising the reaction temperature to 100 ° C, the polymerization reaction was carried out. However, gelation occurred in the reaction mixture.

Comparative Example 4

The procedure was as in Example 1, 474 g (4 mol) Thionyl chloride as the first polymerization catalyst in the Reaction apparatus were given according to Example 1, wherein no polymerization reaction occurred.

Comparative Example 5

The procedure was as in Example 1, 332 g (2 mol) Isophthalic acid instead of trimellitic acid the same Way as used in Example 1, however occurred no polymerization reaction.

Table 1 shows the polymerization conditions and the general physical properties of the in the Examples of PAI resins obtained.  

As can be seen from Table 1, the PAI resins according to the invention are polymers with high molecular weights and an intrinsic viscosity of 0.5 dl / g or more. The tensile strength of the resins measured on films was in the range from 1000 to 1300 kg / cm ² , which shows very good mechanical strength. In order to determine the thermal properties of the PAI resins according to the invention, the glass transition temperatures were measured with a differential scanning calorimeter (DSC).

Claims (4)

1. A process for producing high molecular weight polyamideimide resin which comprises:
Dissolving an aromatic tricarboxylic acid anhydride or its derivative and an aromatic diamine in a polar solvent,
Prepolymerize the resulting solution with a reactant concentration of 5 to 30 wt .-% at a temperature of 50 to 130 ° C for a period of 1 to 5 h by using 5 to 80 mol% (based on the molar sum of the aromatic tricarboxylic acid anhydrides used and aromatic diamines) of an acyl halogenating agent as a first polymerization catalyst to a low molecular weight polyamideimide resin and then
Polymerize at a temperature of 70 to 130 ° C for a period of 1 to 5 h with 1 to 70 mol% (based on the molar sum of the aromatic tricarboxylic acid anhydrides and aromatic diamines used) of a phosphorus compound as a second polymerization catalyst selected from trivalent phosphorus compounds of general formula (RO) ₃ P, wherein R is an aromatic or aliphatic substituent, phosphoric acid, pyrophosphoric acid, phosphorus pentoxide and phosphorus pentachloride, to a high molecular weight polyamideimide resin. 2. The method according to claim 1, in which the produced Polyamideimide resin has an intrinsic viscosity of 0.4 to 1.5 dl / g, measured in a dimethylacetamide solution with a concentration of 0.5 g / dl at 30 ° C.   3. The method according to claim 1, in which the first Polymerization catalyst is selected from thionyl chloride, p-toluenesulfonyl chloride, sulfuryl chloride, cyanuric chloride and Phosphorus trichloride. 4. The method according to claim 1, in which the second Polymerization catalyst is selected from Triphenyl phosphite, tricresyl phosphite, tricyclohexyl phosphite, Dimethyl-m-chlorophenyl phosphite and oxyethyl dipyridyl phosphite.